It's The Astronaut's Wife with the sexes reversed, the story of a returning astronaut altered by some experience in space. Back in the 60s, there was an Outer Limits episode called "Cold Hands, Warm Heart" that told the same story. It's appeared in written fiction, such as one story Samuel R. Delaney wrote...arrgh, I can't remember the title. There's not one original thing in Extant, but I did like the show's quiet approach to telling the story instead of relying on F/X and action sequences.

I'm trying to withhold judgment until #12 has time to finish "cooking" -- as #11 once put it. But it's hard; this initial appearance was so disappointing. Clara is acting as stand-in for the viewers, getting to know the new Doctor.

One thing that I disliked intensely was the cavalier disposal of the lady dinosaur. It was a cute idea, having the Doctor make his entrance like that. But then the writers were faced with the problem of this enormous dinosaur in London. The Doctor yells at her that he's going to save her, he's going to return her to where she belongs...and five seconds later she's killed. Why? She was an encumbrance to the plot, not because the cyborgs needed her. So if something gets in the way of the story, just kill it? That's the worst kind of hack writing.